Variable-speed mechanism.



N0. 803,593. PATENTED NOV. 7, 1905. B. HILL.

VARIABLE SPEED MECHANISM. APPLICATION FILED FEB.17,1905.

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VARIABLE-SPEED MECHANISM.

Specification of Letters Patent.

Patented Nov. 7, 1 905.

Application filed February 17, 1905. Serial No. 246,05 9.

To all whom it may concern.-

Be it known that I, EBENEZER HILL, a citizen of the United States.residing at Norwalk, in the county of Fairfield and State ofConnecticut, have invented a new and useful Variable-S peed Mechanism,of which the following is a specification.

This invention relates to a mechanism for varying the speed of rotationof a driven shaft.

The object of the invention is to provide a mechanism by means of whicha driven shaft may be rotated at a predetermined speed with relation tothe driver or at double that speed, as desired, without shifting belts,gears, or clutches.

The embodiment of the invention that is illustrated has a pulley looselymounted on the driven shaft and containing a box of intermeshingbevel-gears. Two of the gears are carried by the pulley. One is fixed tothe shaft and the other is loose on the shaft, but is provided withmeans for looking it to the shaft and means for holding it immovable.

Figure 1 of the accompanying drawings is a view looking at the face ofthe pulley with. a portion broken away. Fig. 2 shows a centrallongitudinal section of the mechanism. Fig. 3 shows a side elevation ofa brake mechanism that may be used, and Fig. 4 is a view looking at theface of a ratchet and paw] that may be employed for connecting thebrake-gear with the shaft.

The driven shaft 1 may be supported by any suitable bearing and may beused for any desired purpose. The pulleyQ is loosely mounted on theshaft and may be driven by a belt from any source of power at anydesired speed in the direction indicated by the arrows.

The bevel-gears 3 and 4 are mounted so as to turn loosely within the rimof the pulley near the hub. These gears may be mounted on spokes of thepulley, but preferably are mounted on arbors set in the spokes or web ofthe pulley. The bevel-gear 5, which meshes with the gears 3 and 4, iskeyed or otherwise made fast to the driven shaft. The bevel-gear 6,which also meshes with the bevel-gears 3 and 4, is loose on thedriving-shaft.

The hub of the bevel-gear 6 is extended along the shaft in the form of adrum 7, and encircling this drum is a brake-band 8. On

the end of the drum is an arm 9, carrying a sprlng-pawl 10,wh1ch isarranged to engage a ratchet-shoulder 11 on a disk 12, that is keyed orotherwise fixed to the driven shaft.

The ends of the brake-band are shown as fastened to a brake-lever 13.This lever by a rod 14 is connected with a weighted lever 15,that tendsto lift the brake-lever and release the brake, and by a rod 16 isconnected with a piston 17 in a cylinder 18, that is adapted to pulldown the brake-lever and set the brake.

When the pulley is rotated in the direction indicated by the arrows andthe brake is loose, the resistance of the shaft causes the gears 3 and4, which revolve with the pulley, to rotate in the direction indicatedby the arrows on them, and this causes the gear 6, the brakedrum, andthe pawl to rotate in the direction indicated by the arrow on this gear.Immediatel y the pawl engages the ratchet-shoulder 0n the disk fixed tothe shaft and the gear 6 becomes fixed to the shaft, and then as thegear 5 is fixed to the shaft all of the gears stop turning on their axesand become locked so that the pulley and shaft rotate together in thesame direction and at the same speed as if one piece.

The brake may be set or released by hand; but where convenient-as, forinstance, when the shaft is used for driving the governor of a pump oran air-compressorfiuid-pressure may be applied to the piston in thecylinder for the purpose of setting or releasing the brake, and thus mayvary the speed of the governor and the speed of the engine, as is wellunderstood by engineers.

hen the brake is set, the gear 6 is held immovable. With this gearimmovable and the pulley rotating in the direction indicated by thearrows the gears 3 and 4, which revolve with the pulley, of course withthe same number of revolutions, are rotated on their axes by theimmovable gear 6 in adirection opposite to that indicated by the arrowson them, and this rotates the gear 5, which is fixed to the shaft, inthe same direction as the pulley, but at twice the speed. When the brakeis set and the shaft is rotating forwardly, the pawl rides over theratchet.

By simply setting the brake, whether by hand or foot power or'by steam,air, or water, the speed of rotation of the shaft is instantly increasedin the same direction to double the speed at which it was previouslyrotating,

and as this change is afi'ected without the shifting of belts orchanging the meshing of gears this mechanism is particularly adapted foruse with shafts designed to run at high speeds.

The invention claimed is- 1. A variable-speed mechanism having a shaft,a pulley loosely mounted directly on the shaft, four bevel-gears Withinthe pulley, one gear being permanently fixed to the shaft, another beingloose on the shaft, and the other two being mounted on the pulley andeach meshing with both the fixed and loose gears, means for connectingthe loose gear with the shaft, and means for holding the loose gearimmovable and disconnected from the shaft, substantially as specified.

2. A variable-speed mechanism having a driven shaft a pulley loose onthe driven shaft. gears, one gear being fixed to the shaft, anotherbeing loose on the shaft and provided with a brake whereby it may beheld immovable, and two being mounted on the pulley, and aratchet-and-pawl mechanism for connecting the loose gear With the shaft,substantially as specified.

3. A variable-speed mechanism having a driven shaft a pulley loose onthe driven shaft, gears within the pulley, one gear being fixed to theshaft, another being loose on the shaft, a ratchet-and-pawl mechanismfor connecting the loose gear with the shaft, a brake for holding theloose gear immovable, and means for setting the brake, substantially asspecified.

4. A variable-speed mechanism having a driven shaft a pulley loose onthe driven shaft, gears Within the pulley, one gear being fixed to theshaft, another being loose on the shaft, the latter gear having abrake-drum and a pawl, a ratchet-disk secured .to the shaft and adaptedto be engaged by the pawl, and a brake adapted to be applied to the drumfor holding the loose gear immovable, substantially as specified.

5. A variable-speed mechanism having a driven shaft a pulley looseon'the driven shaft, gears within the pulley, two of said gears beingmounted so as to rotate on their axes and revolve with the pulley,another gear being fixed to the driven shaft and another being loose onthe driven shaft. the latter gear being attached to a brake-drum, abrake adapted to be applied to and released from the drum, and a ratchetand pawl adapted to connect the brake-gear with the shaft when the brakeis released, substantially as specified.

EBENEZER HILL.

Witnesses:

HOWARD H. MOSSMAN, HARRY R. WILLIAMS.

